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प्रश्न
Explain the following reaction with a suitable example.
Hofmann elimination reaction
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उत्तर
- When tetraalkylammonium halide is heated with moist silver oxide, it gives quaternary ammonium hydroxide.
- Quaternary ammonium hydroxides on strong heating undergo β-elimination to give an alkene. This reaction is called Hofmann elimination.
- The least substituted alkene is obtained as a major product (in contrast to Saytzeff elimination).
e.g. Hofmann elimination reaction of N, N, N-Triethylpropylammonium iodide
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संबंधित प्रश्न
Write a short note on Hoffmann bromamide degradation.
Identify the compounds 'A' and 'B' in the following equation:
Illustrate the following reaction giving suitable example in each case:Gabriel phthalimide synthesis
Give the structures of A, B and C in the following reactions :
Give the structure of A, B and C in the following reaction:
\[\ce{C6H5N2Cl ->[CuCN] A ->[H2O/H+] B ->[NH3][\Delta] C}\]
Write the reaction of aliphatic primary amine with nitrous acid.
Give a plausible explanation for the following:
Why are amines less acidic than alcohols of comparable molecular masses?
Explain the mechanism of action of hydroiodic acid on 3-methylbutan-2-ol.
Identify 'A' and 'B' in the following reaction and rewrite the complete reaction :
Give the structures of A, B and C in the following reactions :
Account for the following:
Gabriel phthalimide synthesis is not preferred for preparing aromatic primary amines.
Write structures of compounds A and B in each of the following reactions:
Choose the most correct option.
Which of the following compounds will dissolve in aqueous NaOH after undergoing reaction with Hinsberg reagent?
Answer the following
Explain the ammonolysis of alkyl halides.
Mendius reaction is used to convert _____________
Name the process of breaking C-X bond by ammonia in preparation of amines.
Write reactions to bring about the following conversions.
Acetamide to methylamine
Identify the product obtained when benzyl chloride undergoes ammonolysis in presence of excess ammonia followed by the reaction with two moles of methyl iodide.
What product is formed when \[\ce{R - C ≡ N}\] is hydrolysed?
What is the molar mass of the amine formed when acetamide undergoes Hofmann bromamide degradation?
The reduction of alkyl cyanide with sodium and ethanol to give primary amines is, ____________.
Identify the INCORRECT statement regarding Hofmann bromamide reaction.
In aqueous phase the order of basic strength of alkylamine is ______.
Which of the following compounds is obtained when quaternary ammonium hydroxide is strongly heated?
Which of the following does NOT give carbylamine test?
Nitro compounds are reduced by iron scrap and hydrochloric acid to yield one of the following compounds:
Quaternary ammonium salt is formed:
Benzylamine may be alkylated as shown in the following equation:
\[\ce{C6H5CH2NH2 + R - X -> C6H5CH2NHR}\]
Which of the following alkylhalides is best suited for this reaction through SN1 mechanism?
Amongst the given set of reactants, the most appropriate for preparing 2° amine is ______.
Which of the following compounds is the weakest Brönsted base?
Reduction of nitrobenzene by which of the following reagent gives aniline?
(i) \[\ce{Sn/HCl}\]
(ii) \[\ce{Fe/HCl}\]
(iii) \[\ce{H2 - Pd}\]
(iv) \[\ce{Sn/NH4OH}\]
Which of the following amines can be prepared by Gabriel synthesis.
(i) Isobutyl amine
(ii) 2-Phenylethylamine
(iii) N-methylbenzylamine
(iv) Aniline
Which of the following reactions are correct?
(i)
(ii)
(iii)
(iv)
What is the product when \[\ce{C6H5CH2NH2}\] reacts with \[\ce{HNO2}\]?
Write following conversions:
nitrobenzene `->` acetanilide
Describe Gabriel's phthalimide synthesis. (Give reaction)
Which of the following reactions will not give a primary amine?
The compound X is which of the following?
\[\ce{CH3CN ->[Na + C2H5OH] x}\]
Which of the following compound is expected to be most basic?
Which of the following CANNOT be prepared by ammonolysis of alkyl halide?
Give reasons for the following:
Ammonolysis of alkyl halides is not a good method to prepare pure primary amines.
Which of the following compound gives pink colour on reaction with phthalic anhydride in cone. H2SO4 followed by treatment with NaOH?
Methyl amine on reaction with chloroform in the presence of NaOH gives ______.
Which of the following amines can be prepared by Gabriel phthalimide reaction?
- Phenyl methenamine
- N, N - Dimethylaniline
- N - Methyl aniline
- Benzenamine
Choose the correct order of the basic nature of the above amines.
Identify the compo ds A and B in the following reactions:
\[\ce{A ->[Nitrating mixture] B ->[(i) Sn/cone. HCI][(ii) NaOH] Aniline}\]
Write short note on the following:
Ammonolysis
Identify A and B in the following reaction.
\[\ce{C6H5CH2Br ->[Alco.][KCN] A ->[Na/Ethanol][reduction] B}\]
Write a short note on the following:
Ammonolysis
Write the name of reduction product formed when ethyl cyanide is treated with sodium and alcohol.
Write short note on the following:
Ammonolysis
Write a short note on Ammonolysis.
